// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_
#define NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_

#include <stdint.h>

#include <string>
#include <vector>

#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "net/base/net_errors.h"
#include "net/base/net_export.h"
#include "net/http/http_byte_range.h"
#include "net/url_request/url_request.h"
#include "net/url_request/url_request_job.h"

namespace base {
class TaskRunner;
}
namespace file_util {
struct FileInfo;
}

namespace net {

class FileStream;

// A request job that handles reading file URLs
class NET_EXPORT URLRequestFileJob : public URLRequestJob {
public:
    URLRequestFileJob(URLRequest* request,
        NetworkDelegate* network_delegate,
        const base::FilePath& file_path,
        const scoped_refptr<base::TaskRunner>& file_task_runner);

    // URLRequestJob:
    void Start() override;
    void Kill() override;
    int ReadRawData(IOBuffer* buf, int buf_size) override;
    bool IsRedirectResponse(GURL* location, int* http_status_code) override;
    std::unique_ptr<Filter> SetupFilter() const override;
    bool GetMimeType(std::string* mime_type) const override;
    void SetExtraRequestHeaders(const HttpRequestHeaders& headers) override;

    // An interface for subclasses who wish to monitor read operations.
    virtual void OnSeekComplete(int64_t result);
    virtual void OnReadComplete(IOBuffer* buf, int result);

protected:
    ~URLRequestFileJob() override;

    int64_t remaining_bytes() const { return remaining_bytes_; }

    // The OS-specific full path name of the file
    base::FilePath file_path_;

private:
    // Meta information about the file. It's used as a member in the
    // URLRequestFileJob and also passed between threads because disk access is
    // necessary to obtain it.
    struct FileMetaInfo {
        FileMetaInfo();

        // Size of the file.
        int64_t file_size;
        // Mime type associated with the file.
        std::string mime_type;
        // Result returned from GetMimeTypeFromFile(), i.e. flag showing whether
        // obtaining of the mime type was successful.
        bool mime_type_result;
        // Flag showing whether the file exists.
        bool file_exists;
        // Flag showing whether the file name actually refers to a directory.
        bool is_directory;
    };

    // Fetches file info on a background thread.
    static void FetchMetaInfo(const base::FilePath& file_path,
        FileMetaInfo* meta_info);

    // Callback after fetching file info on a background thread.
    void DidFetchMetaInfo(const FileMetaInfo* meta_info);

    // Callback after opening file on a background thread.
    void DidOpen(int result);

    // Callback after seeking to the beginning of |byte_range_| in the file
    // on a background thread.
    void DidSeek(int64_t result);

    // Callback after data is asynchronously read from the file into |buf|.
    void DidRead(scoped_refptr<IOBuffer> buf, int result);

    std::unique_ptr<FileStream> stream_;
    FileMetaInfo meta_info_;
    const scoped_refptr<base::TaskRunner> file_task_runner_;

    std::vector<HttpByteRange> byte_ranges_;
    HttpByteRange byte_range_;
    int64_t remaining_bytes_;

    Error range_parse_result_;

    base::WeakPtrFactory<URLRequestFileJob> weak_ptr_factory_;

    DISALLOW_COPY_AND_ASSIGN(URLRequestFileJob);
};

} // namespace net

#endif // NET_URL_REQUEST_URL_REQUEST_FILE_JOB_H_
